Decades-Old Waste Barrels Are Creating Toxic Dead Zones off LA’s Coast

Until 1972, the Pacific waters of Southern California served as a dumping ground for hazardous and industrial wastes. More than 50 years later, corroded metal barrels still litter the seafloor off the coast of Los Angeles, and scientists are only beginning to understand the consequences of casually tossing them into the ocean.

Images of the barrels first surfaced in 2020, with some of them encircled by mysterious white halos on the seafloor. Experts initially linked the barrels to DDT—a toxic pesticide that Montrose Chemical Corporation regularly dumped nearby—but an EPA investigation could not confirm that hunch. Now, researchers have discovered that the halo-encircled barrels actually contained caustic alkaline waste that transformed parts of the seafloor into extreme environments